Harlem Hospital serves a black population with a preterm delivery rate about twice the national average. We propose, in 1986-87, to evaluate programs for the prevention of preterm delivery. The efficacy of secondary prevention through early detection of preterm labor, and of primary prevention through prenatal education, will be tested in a randomized controlled trial in women with prior preterm deliveries or late spontaneous abortions. The focus on these high risk women, with a 15% risk of preterm delivery, reduces the sample sizes needed and ensures motivation. At registration 430 high risk participating women will be assigned at random to one of two clinics, B and S. Clinic B (Basic High Risk Care) will provide continuity of care, weekly visits, general advice, and a telephone with access to a line manned 24 hours. Clinic S (Special High Risk Care) will provide, in addition, special education on self-detection of uterine contractions and on individual regulation of physical activities. A random half in each clinic will be provided with telemetric uterine monitors for home use, resulting in four groups in all (Bm, Bo, Sm, So). Uterine contractions during 30 minutes rest will be recorded daily and transmitted to a central unit by telephone. For Sm the record will be read daily and acted on; for Bm the record will be stored and evaluated later. A lower rate of preterm delivery in Clinic S vs. Clinic B will demonstrate an effect of early detection of preterm contractions combined with the individual regulation of physical fatigue. Superiority of Sm vs. So will demonstrate an effect of early detection by telemonitoring over self-palpation. Lower rates in Clinic B than those of matched high risk women seen prior (1982-83) to institution of Clinic B will indicate an effect of Basic High Risk Care over routine care (provided that secular changes are accounted for by reference to rates for comparable populations). Estimates of the statistical power for the proposed comparisons have been made. Dr. Ng is a board-certified pediatrician and epidemiologist dedicated to a research career. His particular research interests are in reproductive and neuro-developmental epidemiology. Prof. Stein is a world-renowned epidemiologist in these fields; Prof. Chao is a leading clinical obstetrician at Columbia University and Prof. James is a world authority in perinatal medicine. Their guidance and counselling will ensure the success of the research.